Electric generating system and apparatus



y 1936 D. s. 0pm: ET AL 2,040,470

ELECTRIC GENERATING SYSTEM AND APPARATUS Filed "Oct. 29, 1932 2 Sheets-Sheet 1 INVENTOR. Da/e S Co/e am/ BY Leonard S Spat/7.

ATTORNEY.

May 12, 1936. D. s. COLE ET AL ELECTRIC GENERATING SYSTEM AND APPARATUS Filed Oct. 29, 1932 2 Sheets-Sheet 2 INVENTOR. Da/e $Co/c"ano Leonard SS eLII.

l 1 I I 1 I l I l l l l mmfm:

Patented May 12, 1936 UNITED STATES PATENT OFFICE 4 T, 2,040,410

- Dale 8. Cole, Cleveland Heights, and Leonard 8. Speth, Cleveland, Ohio, assignors, by meane assignments, to The Leeee-Neville Company, Cleveland, Ohio, a corporation of Ohio Application October 29, 19:2, Serial No. 640,204

Ibis invention relates to electric generating systems and apparatus, and particularly to generating systems and apparatus in which an electric generator is rotatably driven by a variable 5 speed source of power.

Typical of such generating systems and apparatus is that employed on automotive vehicles. wherein an electric generator is driven, by the vehicle engine.

Such systems commonly include a storage battery, lamps and other apparatus energized by Y current from the generator, and various means have been accordingly devised to regulate or control the output of the variable speed generator to The control of the generator output by regulating its voltageyis generally recognized as superior to the current regulation, particularly so when storage batteries andlamps are to be energized by the generator; but its general adoption has been preventedpy the relatively great cost of the apparatus accessory to the generator by which the voltage regulation is effected.

35 Ina typical voltage regulation system and apparatus for example, a regulating panel is provided on which is mounted an electro-magnetic relay having its winding energized proportional to the generator voltage: and the contacts of the 40 l relay control the energizationof the generator ,tield winding. Upon arise or voltage above the predetermined desired value, the relay contacts are operated magnetically to break the field winding circuit, or to insert resistance in series 4! with the field winding or otherwise to weaken the acid to effect a reduction of voltage.' when the voltage falls to the predetermined value, the relay contacts are operated by a spring to restore the ileld circuit. In operation, such relays open 50 and close rapidly with a vibratory movement. The continuous vibratory operation 01' such 1 regulating relays to repeatedly'break the highly inductive field circuit, orrto repeatedly insertie' bistance thereintwis attended by destructive are- 55 mg and rapid deterioration of the relay 19 Claims. (CL 171-313) and this together with the added cost of manufacturing and installing such regulator panels and the vibratory electro-magnetlc relays andother necessary parts thereon has largely prevented the general adoption of the voltage regu- 5 latedgenerator system for automotive vehicles, and has confined its use to a limited field of application.

In a copending application filed by us on June 3, 1932, Serial No. 615,170 for Improvements in 10 electric generating systems, thereis illustrated and described an improved electric generating system and apparatus whereby the voltage output of a variable speed electric generator may at all speeds within apredetermined working speed range, the voltage regulation being ,efiected-by a vibratory relay respectively opening to insert a resistance in the field circuit and closing to short-circuit it, upon the attainment of 20 generated voltage above a predetermined value I or respectively falling to or below the predetermined value. In said application is illustrated and described a system in which the cost of manufacturing and installation of the parts isreduced to the minimum by mounting the .vibratoryrelay directly upon the frame of the generator to dispense with the cost; or a supporting panel and, accessory wiring. In the system described in that applicationfurthermore, one of the field windings, or an accessory iield winding, provided on one of the ileld poles is energized reversely or in a bucking relation to the normal polarity of thatpole, and the magnetic circuit oi. the vibratory relay is 36 energized by flux generated by said reverse wind-- ing. Among a number of very important advantages resulting from this arrangement arethat a separate winding for the relay is unnecessary and the costof the regulating equipment is-there- 40 .by reduced; and that, due to the functioning of the reverse fleld'winding, as fully described in that application, the field strength of the generator dies out very rapidly upon opening of the relay contacts to insert resistance in the held 45.

circuit, and thus the tendency to are at the relay contacts is'reduced to the minimum or substantially completely destroyed; and that the rapid dying out of the ileld flux not only increases the rate of vibration of the relay and therefore eilects a more nearly non-fluctuating output from the generator, but the reduction or complete e1imina-- tion 01.. arcing eflected thereby makes it possible smaller-more compact relay parts to coat of the apparatus and U be regulated to a substantially constant value 15 r in addition prolongs the life thereof almost indefinitely.

One of the advantages furthermore of such a system and apparatus as described in said application is that it may be applied to existing generators, such for example as third brush current regulation generators to transform them into voltage regulation generators, or into generators which limit their current output by their third brush and which limit their voltage output by the voltage regulation accessory parts.

In said application also we have illustrated and described one form of an accessory apparatus which may be applied to a commercial generator, for example of the third brush current regulation type, to transform it into a voltage regulation generator. 1

It is an object of the instant application to provide an improved means whereby a variable speed generator whose voltage varies with its speed, may be adapted to deliver a substantially constant voltage output at all speeds within a workin speed range. 7

Another object is to. provide an improved means in the form of an accessory apparatus which may be applied to a non-voltage regulating generator to transform it or adapt it to de- 7 liver a substantially constant voltage.

Another object of this invention is to provide such an accessory device which may be applied to a commercial generator without the necessity of performing any machine operations upon the existing generator or otherwise modifying it physically. V

Another object is to provide an improved accessory or like apparatus which may be applied to an existing generator to convert it into a voltage regulation generator and comprising a bucking field winding and a voltage-regulation vibratory relay energized thereby and means for attaching it to the existing generator in an improved manner.

Another object is to provide a voltage-regulating vibratory relay for generators of improved construction. I

Another object is to provide a voltage-regulation vibratory switch for generators having im- P oved means for enclosing it against the acoumulation thereon of dust and dirt.

Another object is to provide as an accessory device for existing generators, an improved switch construction comprising in unit form a cut-out switch for the generator load circuit and a vibratory voltage regulating relay and an energizin winding for both, which winding also functions as a bucking field winding in connection with the voltage regulation. 1

Another object is to provide a device of the class referred to which will be cheap to manufacture and install and which will eifect improved emcient operation,

Another object is to provide for electric generators, an improved switch construction comprising in unit form a cutout switch for the genorator load circuit and a vibratory voltage regulating relay having magnetic circuits energized responsive to generated voltage, and a single adjusting means for adjusting the cut-out switch and the relay to adjustably vary the voltage to which they operatively respond.

0therobject swillbe apparentto those skilled in the art to whichmy invention appertains.

Our invention is fully discloeedin the following description taken in connection with the accom- JNIIIIK drawlms, in which:--

Fig. 1 is a plan view partly in cross-section and mercial generator and with an embodiment of my invention applied thereto;

Fig. 2 is a cross-sectional view taken approximately from the plane 2 of Fig. 1;

Fig. 3 is a view generally similar to Fig. 2 but taken from the plane 3 of Fig. 1;

Fig. 4 is a fragmentary view taken from the plane 4 of Fig. 2;

Fig. 5 is a fragmentary view taken approximately from the plane 5 of Fig. 2; Fig. 6 is a diagrammatic view of an electric generating system with which our invention may be practiced and illustrating in simplified diagrammatic form some of the elements of Figs. 1 to 5 inclusive;

Fig. 7 is a view similar to a part of Fig. 1 illustrating a modification;

Fig. 8 is a view taken from the plane I of Fig. '7;

Fig. 9 is a diagrammatic view similar in general to Fig. 6,but illustrating the employment of the form of our invention illustrated in Figs. '7 and 8;

Fig. 10 is a sectional view taken from the plane III of Fig. 8;

Fig. 11 is a sectional view taken from theplane ll of Fig. 7;

Fig. 12 is a fragmentary diagrammatic view illustrating another form in which our invention may be practiced.

Referring to the drawings we have shown generally at l a cylindrical hollow shell such as employed in commercial generators and at 2 and 3, respectively, end covers or housing portions. At 4 and 5, respectivey, are pole pieces secured to the inner wall of the shell i, the shell thus constituting a return path or yoke for the field flux.

In Figs. 2 and 3 we have illustrated also at i, in simplified form, an armature, and at 1 a shaft therefor, these parts being omitted for simplicity from Fig. l, but as will be understood, the shaft 1 may be rotatively mounted in suitable hearings in the end housing members 2 and 3. At I and 9 are indicated field windings on the pole pieces 4 and 5 respectively.

At II is illustrated a winding which is preferably made, according to usual practice, from numerous turns of relatively small wire wrapped into a unit by suitable tape wrapping as indicated at l I. The winding ll has a large loop portion l2 formed to substantially embrace one of the field poles such as the pole I and is preferably large enough to be placed around the outside of substantial portion thereof and the ends i3-|I of the winding III are carried axially along the generator and are formed into a plurality of turns ll --l4 constituting a winding II for energizing a voltage regulation vibratory relay, to be tiescribed.

Generators of the usual commercial construction are provided with an aperture in'the shell I as indicated at Ii, Figs. 2 and 3, which aperture is generally of rectangular form and is generally provided for the purpose of giving access to the generator brushes.

In the practice of our invention we employ this aperture as a means to support and position the voltage regulation relay embodied in our invention. Preferably we form from sheet metal a panlikebase l1 havingabottomportion ll, side walls ll-ll and a peripheraiflange II, The pan is or such size and shape that the side walls "-19 just fit within the periphery of the aperture l3 and the flange 20 overlaps the shell of the generator around the aperture.

As will be described, parts of the voltage regulating relay are mounted on the base I! of the pan and with make and break switch contact parts on the concave side of the pan. These parts are thus shielded from the accumulation of carbon or copper dust which may be thrown ofi from the generator commutator and brushes. To secure the pan and therefore its'associated parts in position, we employ the band 2| which is normally employed to cover up the aperture ii in commercial generators. This .band is usually iormed from sheet metal, is wrapped around the generator shell and is wide enough axially of the generator to entirely cover the aperture IS. The band may be provided with a pair of cars 2222 at its adjacent ends through which a bolt 23 may.

be projected to draw the ends of the-band together to clamp them tightly upon the generator. When this band is wrapped around the generator and over the pan flange 20, it rigidly secures the pan, in the aperture l5 by its clamping action, and furthermore by covering the entire pan shields the parts mounted on the concave side of the pan from the accumulation of dust or dirt from outside the generator. The band thus performs a double function.

Projecting downwardly from the bottom IQ of the pan is a pair of spaced elements 24 and 25 formed from steel or other ferrous sheet metal having respectively ears 26 and 21 projected upwardly through perforations in the pan bottom I! and bent over parallel therewith and riveted thereto by rivets 28,-28, see particularly Fig. '5.

A bolt of iron or like ferrous metal 29 is projetted through aligned perforations in the elements 24 and 25 and clamps therebetween an insulatiiig sleeve 30 and heads of insulating material 3|3|. The winding l5, above described,

is disposed around the bushing 30 and an electromagnet is thus provided,. comprising a core 23, pole pieces 21 and 2B and a winding ii on a spool 3i. The pan is preferably formed from nonmagnetic material such as brass so as not to short-circuit the magnetic path between the pole pieces 26, and 21. An armature 33, formed from ferrous metal, is riveted as at 34 to a flat resilient springelement extending from the armature and rigidly secured by a screw 38 and a thick washer 31 to the pan bottom. The armature 33 is disposed over the pole pieces or ears 21 and 23 and when the magnetic circuit above described is sufllciently energized, is attracted toward the pole pieces being slightly spaced therefrom to provide 4 suitable working air gaps in a well known manner.

The spring 35 tends to hold the armature away from the pole pieces and its retractile force may be adjusted by a stud 38 screwed into the pan bottom and having a collar 39 engaging the under side ofthe spring 35,- a screw-threaded shank end thereof projecting upwardly through a suitableperforation in the spring.

The spring 35- is shaped so as to tend normally to hold the arms.-

ture too close to the pole pieces 26 and 21 and thus presses upon the collar v39. If desired, the

spring may be shaped so as to tend normally to hold the armature too far. from the pole pieces and accordingly the collar 33 may be disposed on the other side of the spring,

The free end of the armature 33 carries a contact 43 engageable, in the retracted position of riedon a bracket 42 which is rigidly secured on the pan bottom and insulated therefrom in the following manner.

A screw 43 is projected throughthe bracket 42 and through an aligned perforation in the pan 5' bottom l3 and into a bracket 41, the latter serving as a nut. Suitable insulating strips 45-45 on opposite sides of the pan bottom and. an insulating washer 46 surrounding the screw insulates the screw and therefore thebracket 42 10 from the pan bottom. The bracket 4! is provided with a terminal connection screw to which an electric circuit wire may be attached.

A block of insulating material 50 has wound It will thus be observed that both the contact 40 and the said end of the resistance wire Si '25 are grounded upon the pan bottom; and that the other contact II and the other end of the resistance wire 5| are insulated from the pan and from other grounded parts of the generator and terminate electrically at the terminal screw 43. 30

The electric circuit connection of the parts above described which will presently be considered, is so arranged that the ampere turns of thewinding "I oppose those of the field winding 3; and that the resistance 5| is inserted in the om as cult when the contacts 43-" are opened.

The electric connectionsand mode of opera tion and function of the parts thusfor described may be more clearly understood by reference to the diagram of connections Fig. 6. In this figure, is

some of the mechanical parts of Figs. 1 to 5 are I shown reproduced in simplified form, among which are the pole piece 4 of the generator, the loop l2 of the winding 10 embracing this pole piece, the winding l5 energizing the pole pieces 45 26 and 21 of the vibratory relay, the armature 33 thereof and the contacts 43 and 4| together with the resistance unit 5|.

It will now be understood that. the generator shown generally at ill is energized by'the field 5 windings 3 and 9, the winding 2 opposing the field windings.

The main load circuit of the generator may be traced from its brush 8| through wires and 63 either to a battery 64 or to a load-line 65 from 5 which it may energize lamps or the like 65, and s then may be traced by a return line 81, from the lamps 66 and a return line 58 from the battery 34, and by way of wires G9 and Ill back to the brush H of the generator.

The fields 8 and 8 are ,energized across the brush II and a third brush 12. The circuit me! be traced from the brush 12 through the windings 8 and 3 and thence by wire 13 to' the point "Ii where the circuitis optional, either through the' resistance 5| or through the contacts. 40 and 4| .around the resistance when the contacts are closed to the point 14 and thence by wire I3 and wire I0 back to the brush 1|. Y The winding loop I2 opposing the'field 3 is 70 energized across the brushes 3| and" by circuit including the wire 32, a wire 11, the loop l2 and thewinding II in'serles and th'ence'by awirelltothewire" andbackl'tothebrush'll. the armature 33, with astationary contact 4| car- In operation, when the generator attains abet- 7 taln predetermined speed and regulating voltage, the energization of the winding II is suiilcient to open the contacts Hi and insert the resistance II in the ileld circuit to weaken the ileld and effect a reduction of voltage. The opposing energisation by the loop I! hastens the decay of ileld strength in a manner more fully described in the above-mentioned application, and for the purposes and advantages fully set forth therein.

Upon the decay oi the flux and corresponding decay of the voltage to the regulating value, the armature 33 is retracted and closes the contact. short-circuiting the resistance II and permitting the voltage again to rise, and so on.

The vibratory relay construction including the pan and the parts secured thereto as above described and the winding II on the relay core connected with or integrally formed with the winding ll may be constructed as a unit completely assembled and it may be installed upon a commercial generator to convert it into a voltage regulation generator merely by removing the band 2| inserting the loop I 2 through theaperture It, it around the winding 8 connecting the winding II in the generator circuit, and seating the pan in the aperture and replacing the band 2|. I

11' desired, of course, tape or other means may be applied to more firmly secure the loop II in position.

The slight changes in the electric circuit from that oi the commercial generator will beobvious to those skilled in the art, particularly in view oi the diagrammatic showing of Fig. 6. It is customary to ground thebrush ll.

, In Figs. 7, 8 and 9 we have illustrated a modification of our invention in which is included the cut-out switch commonly employed in variable speed generating systems to disconnect the generator irom its load circuit when the speed and voltage fall below a predetermined value and to connect it again to the circuit when the voltage rises to the predetermined value.

Referring to the diagram of Flg. 9, such a system is shown.

As illustrated in Fig. 9, the winding ll corresponding to the winding I I above described embraces or encircles, besides the magnetic circuit comprising the armature I3 and pole. pieces 28 and 21, a second magnetic circuit comprising pole pieces II and II disposed to energize and at.- 1

tract'an armature l2 against the resilience of a spring 33 to close a pair of contacts." and CI.

The winding ll is integral with and in series with a loop I! corresponding to the loop I! of the nrst iorm encircling the pole piecel oi' the generator.

The circuits oi the diagram oi Fig. 9 are substantially the same as of Fig. 6 except that the main ll, connected to the brush ll instead of leading directly to the battery and load circuit, goesilrstby wayoi'awlrel'ltothecontactll; the other contact I4 is connected to a winding ll around the pole piece II, which is connected to the line I. When the contacts Cl and I are closed, the circuit is completed through the con-' tactsandthroughthewirellandsoonasin In the operation of the apparatus and connections of Fig. 9, when the speed or the generator causes it to reach a predetermined voltage, the

energimtion oi the winding II will cause the contacts 04-" to close and thereafter they will be held closed partly by the winding w andpartlybythewiuding I m e r'fl have ears'extending upwardly .tions in the bottom-ll and may provide air gaps voltage falls below the predetermined value, it is desirable that the contacts ll-II shall open in order to prevent the battery 4 from dischargingbackward through the To this end. the winding It is employed and, as will now be a understood, ii current from the battery tends to flow backward through the line HI and through the winding II, it will oppose any remnant of magnetism in the pole piece II and destroy the magnetic pull and permit the contacts iii to open.

The same winding ii acting on the armature 33 will eilect voltage regulation as described for Fig. 6.

Thus in this form, the single winding |lll' energized proportionate] to the gmerator voltage performs three iun'c ons: that oi! the bucking loop [2' (corresponding to the loop i! of the other form), that of voltage regulation by the armature 33, and that or cut-out function by the armature 82. Thus the maximum economy is *eil'ected.

One form of embodiment of the apparatus illustrated diagrammatically and discussed above in connection with Fig. 9 is illustrated in Figs. 7. 8, 10 and 11. Herein, the same pan i1 is shown as in the other form upon the bottom ll of which the switch and relay elements are secured. As shown in Figs. 7 and 8, the relay armature l3 and resistance block it and' resistance wire II are made slightly smaller in transverse dimension in order to leave room for the armature I! of the cut-out switch.

As shown in Fig. 11, the cut-out switch armature I! may be secured at its rearward or righthand end as viewed in Fig. ll in a manner similar to that for the armature 13 above described. Its opposite end may be bent upwardly as at II and provided with a contact II. A stationary contact 84 maybe secured'to and insulated from 40 the pan bottom it as shown generally at II and may be engaged by the contact II when the latter is magnetically depressed in a manner to be described.

To provide magnetic energization for both ar- (5 matures II and ii, there may be secured to the pan bottom II as shownin Fig. 8, supplemented bolt 2! ot i the magnetic circuit for the armature so 33, and an -additional pair of depending pole pieces li-Il for supporting acore bolt 2! similartotheboltilioramagn'eticcircuitoithe armature- II. The pole pieces II and .through perlorall between the pole pieces and the armatures as fully described for the first form hereinbeiore.

The winding II above described may encircle or embrace both boltsll and 2| to magnetically G0 energize the same.

Inthisform,thewinding il'maybeconflned to a portion, longitu considered, or the bolts 2! and II; and the bolt Il may have wound thereon the winding ll referred to in connection with Fig. 9.

winding l5, corresponding to the generated voltage, will effect operation of the vibratory relay armature I3 to eiIect voltage regulation as described hereinbeiore, and the same energization will attract the armature 82 to close the contacts be magnetically attracted by the magnetism gen-,

erated-by the winding it, at substantially the same voltage value. To this end, a bridge piece in: may span the side walls oi the pan i1 Centrally thereof, a screw I03 may be mounted in the bridge piece and adapted to rotate in a perioration therein substantially without axial movement. The inner end of the screw I03 may be threaded into a block I having secured thereto a pair springs I and it. The springs Hi5 and I06 may be formed from flat resilient metal secured at one end of the block Ill and at their opposite ends engaging the upper sides 0! the armatures 82 and 33. r

To prevent revolution of the block I and its springs around the axis of the screw I, the outer ends 0! the springs I" and I18 may seat inslight depressions in the upper sides of the armatures as indicated in Fig. 8.

As will now be apparent, upon turning'the screw I03, the block I04 will be propelled inwardly outwardly to vary the tension of the springs I05 and it onto their armatures 33 and 82 to vary their responsiveness to the magnetic traction. To this end the springs I05 and I" are preferably made identical.

with this adjustment means, the, cut-out switch will not close and'connect the battery and the work circuits to the generator until the gen erated voltage has reached the regulating voltage; and i! the regulating voltage be adjustably changed, the same condition will be obtained because the adjustment oi the cut-out will correspondingly be changed. In Fig. 12, a modification 01' the construction of the reverse field winding and the winding en' ergizing the voltage regulating relay or voltage" regulating relay and cut-out switch is illustrated. In this form, the reverse winding 95 embraces only the pole piece I, and a separate winding more in the form of a spool ,9! is provided to energize the local magnetic circuit of the regulating relay oroi! this relay and the cut-out switch. The two windings 95 and 86 are connected in series as illustrated and thus their functions and mode or operation are not altered by this diilference oi construction; and furthermore, the two windings 95 and 85 may be assembled together with the magnetic circuits of the relay or of the relay and cut-out switch and applied as a complete accessory device to a commercial generator to convert it into a voltage regulating genzrator with an improved cut-out switch and ciruit.

Whereas hereinbeiore we have described generators oi the two-pole type, it will be understood that our invention may be applied. to a multipolar generator and a reference to this type of generator and system may be round in the above-mentioned application.

Our invention is not limited to the exact details of construction shown and described. Other changes and modifications may be made therefrom without departing from the spirit and scope oi the invention and without sacrificing its advantages.

We claim:

1. In an accessory apparatus adapted to be applied to a variable speed variable voltage generator oi the type having an aperture in the generator irame wall, to convert the generator into a substantially constant voltage generator, 9. base adapted to be disposed in the aperture, switch contacts and a magnetically tractable switch operating armature on one side of the base, an energizing ferrous magnetic circuit for the armature on the other side of the base comprising a core element and magnetizable elements extending through the base into proximity with the switch operating armature, a winding on the core element and a loop of the winding formed and disposed to be looped around a field pole of the generator.

contacts controlled by movement of the armor" ture, a winding ior the core element, a circuit for energizing the winding commensurably with voltage generated in the armature. and connections for including the contacts in series with the load circuit, and a removable band extending around the generator frame over the aperture and switch and upon removal giving access to the switch.

3. An electric enerator construction as described in claim 2 and in which the base is in the form of an outwardly open pan seated in the aperture and the switch contacts are in the pan.

4. In an electric generator construction, a gen- I erator frame comprising a walled compartment, an aperture in the compartment wall, a generator armature positioned in said walled compart- -ment, connections for connecting the annature to a load circuit, a field pole having a winding whereby it'may be energized with magnetic flux o! a normal polarity by current generated in the armature, a winding of opposite polarity on the pole and a circuit whereby it may be energized commensurably with voltage. generated in the armature, a switch base disposed inthe aperture and secured upon the compartment wall, a pair of electro-magnetic switches supported on the base each comprising a ferrous core element and a magnetically tractable armature and switch contacts controlled by movement of the annature, and the winding or opposite polarity having a portion thereoi looped around both ferrous core elements to energize the same, connections for once! the switches for including its contacts in I a circuit controlling field energization of the gen erator and connections for the other switch for erator frame comprising a walled compartment, an apertm'e in the compartment wall, a generator armature positioned in said walled compartment a switch base disposed in the aperture and secured upon the compartment wall, a pair of electro-msgnetic switches on the base comprising each a ferrous core element, a magnetically tractable armature and switch contacts controlled by movement of the armature, connections for one set of contacts for including the contacts in a circuit controlling the energizatlon of the generator field and connections for the other set of contlcts for including the contacts in the load circuit, and a single winding for both core elements, and

a circuit {or energizing said winding commensurably with voltage in the armature. v

7. In an electric generatingsystem, a variable speed generator, comprising an armature and a work circuit, a cut-out switch comprising a magnetically tractable armature and contacts connected in the work circuit for closing and opening theyork circuit and operable by the magnetically tractable armature at predetermined high and low generator voltage values, a relay comprising a agnetically tractable armature and contacts connected in a circuit controlling the field energisation and operable by said magnetically tractable armature responsive to predetermined high and low voltage values to maintain the generator voltage substantially constant, a magnetic circuit for each armature comprising a core element, a common winding for both core elements, a circuit for energizing said winding commensurably with voltage generated in the armature and separate resilient means for retracting the switch and relay armatures and a common adjusting means for adjusting the resilient means of both the switch and relay to simultaneously vary their operating voltages.

8. In an electric generating system, a variable speed generator, comprising an armature and a work, circuit, a cut-out switch comprising a magneti'cally tractable armature and contacts connected in the work circuit for closing and opening the work circuit and operable by the magnectically tractable armature atpredetermined high and low generator voltagevalues, a relay comprising a magnetically tractable armature and contacts connected in a circuit controlling the fleld energimtion and operable by the magneticallytractable armature responsive to predetermined high and low voltage values to maintain the generator voltage substantially constant.

a magnetic circuit for each armature comprising a core element, a common winding for both'core elements, a'circuit for energizing the winding oommensurably with voltage generated in the armature, separate resilient means for retractingthearmaturesoftheswitchandreiayand separate adjusting means for the resilient retractingmeans to adjust the operating voltages of the switch and relay, and a common adjusting" means for simultaneously varying the resilience the adjusted voltages.

9. In an electric generating system, a variable speed generator, comprising an armature and a work circuit, a cut-out switch comprising a magnectically tractable armature and contacts connected in the work circuit for closing and openingtheworkcircuitand'operableby the magnetically tractable armature at predetermined and switch contacts controlled by movement of high and low generator voltage values, a relay comprising a magnetically tractable armature and contacts connected in a circuit controlling the field energizatlon and operable by the magnetically tractable armature responsive to predeter- 5 mined high and low voltage values to maintain the generator voltage substantially constant, a magnetic circuit for each armature comprising a core element, a common winding or both core elements, a circuit for energizing the winding 10 commensurably with voltage generated in the armature, separate resilient retracting means for the relay and switch, separate adjusting means for the resilient retracting means to adjustably vary the operating voltages of the switch and relay and a common adjusting means for simultaneously varying both the resilient retracting mes-m to adjust the said voltages, the separate adjusting means permitting adjustment of the switch and relay to operate at the same voltage and the common adjusting means permitting this voltage to be varied.

10. In an electric generator construction, a generator frame comprising a walled compartment, an aperture in the compartment wall, a generator armature positioned within said walled compartment and adapted to be connected to a load circuit, a switch base disposed in the aperture and secured upon'the compartment wall, said base having at least a portion thereof shaped to substantially close the aperture, an electromagnetic switch supported on the base comprising a magnetic circuit including a ferrous core element and a magnetically tractible armature $5 the armature, a winding for the core element, a circuit for energizing the winding commensurably with voltage generated in the armature, and a removable band disposed around the generator frame and the switch and when removed giving to access to the switch.

11. In an accessory apparatus adapted to be applied to a, generator of the type having an aperature in the generator frame wall, a base in the form of a pan disposable in the aperture and is having a peripheral flange adapted to overlap outeredge portions of the aperture, switch contacts and a magnetically tractable switch operating armature on the base, a magnetic circuit for the armature on the base comprising acore elc- 50 ment, and a winding on the core element.

12. In an accessory apparatus adapted to be applied to a generator of the type having an aperture in the generator frame wall, a base in the form of a pan disposed in the'aperture and 6 having a peripheral flange adapted to overlap outer edge portions of the aperture, switch contacts and a magnetically tractable switch operating armature on the base, a magnetic circuit for the armature on the base comprising a core ele- 001 ment, a winding on the core element, and a band 0 around the generator frame covering the 13. An accessory apparatus as described in claim 11 and in which the switch contacts and 6.5.

switches adapted to be energized by voltage of the generator and having. a portion formed to embrace a pole of the generator.

15. In an electric generator construction, a

. generator frame comprising a walled compart ment having an aperture in the compartment wall, a generator armature disposed within said walled compartment, a field pole having a winding whereby it may be energized with magnetic flux of a normal polarity by current generated inv the armature, a winding of opposite polarity on the pole and acircuit whereby it may be energized commensurably/with voltage generated -=in the armature,- a switch base disposed in the aperture and secured upon the compartment wall, an

electro-magnetic switch supported on the base and comprising a magnetic circuit including a fer-i rous core element, .a vibratory armature and switch contacts controlled by movement of the armature, and the winding of opposite polarity having a portion thereof looped around the ferrous core element, said base being of pan form and seated in theaperture and having a periph-r eral flange overlapping the outer edge of the aperture, and the switch armature and contacts being disposed in the pan and the ferrous core element and winding portion being disposed under the pan.

16. In an electric generator construction, a generator frame comprising a walled compartment having an aperture in the compartment wall, a generator armature disposed wiihinsaid walled compartment, a field pole having a winding whereby it may be, energized with-magnetic flux of a normal polarity by current generated inthe armature, awinding of opposite polarity on the pole and a' circuit whereby it may be energized commensurably with voltage generated in the armature, a switch base disposed in the aperture and secured upon the compartment wall, an electro-magnetic switch supported "on the base I and comprising a magnetic circuit including a ferrous core element, a vibratory armature and switch contacts controlled by movement of the armature, and the winding of opposite polarity having a portion thereof looped around the terrous core element, and said base beingof pan form and seated in the aperture and having a peripheral flange overlapp the outer edge of the aperture, and the switch armature and contacts being disposed in the pan and the ferrous core element and winding portion being disposed under the pan, said magnetic circuit including ferrous portions extending from the ferrous core element .through the-pan bottom into proximity with the armature. E

, 1'7. In an electric generator constructionfa generator frame comprising a walled compartment having an aperture in the compartment wall, a generator armature disposed within said walled compartment, a field pole having av winding whereby it maybe energized with magnetic flux of a normaLpolarity by current generated inv the armature, a winding of opposite polarity on the pole and a circuit whereby it may be energized commensurably with voltage generated in the armature, a switch base disposed in the aperture and secured upon the compartment wall, an electro-magnetic switch supported on the base and comprising a magnetic circuit includinga ferrous core element, a vibratory armature-and switch contacts controlled by movement of the armature, and the winding of opposite polarity having a portion thereof looped around the ferrous core "element, said base having the switch armature and contacts disposed on the outer side thereof and the ferrous core element and winding portion on the inner side thereof, and the base also having a flange overlapping the outer edge of the aperture, and a band-like element clamped upon and around the generator frame and clamping the base upon the frame at the aperture.

18. In an electric generator construction, a generator frame comprising a walled compart- -ment having an aperture in the compartment wall, a generator armature disposed within said walled compartment, a fleld pole having a winding whereby it may be energized with magnetic flux of a normal polarity by current generated I in the armature, a winding of opposite polarity on the pole and a circuit whereby it may be energized commensurably with voltage generated in the.armature, a switch base disposed in the l aperture and secured upon the compartment wall, an electro-ma-gnetic switch'supported on the base and comprising a magnetic circuit ineluding a ferrous core element, a vibratory armature and switch contacts controlled by movement of the armature, and the winding of opposite polarity having a portion thereof looped around the ferrous core element, said switch base being of pan form and seated in the aperture and having a peripheral flange overlapping the outer edge of the aperture, and the switch arma-' ture and contacts being disposed in the pan and adapted to be disposedjn the aperture, switch contacts and a magnetically tractible switch operating armature on the abse outwardly thereof, an energizing ferrous magnetic circuit for the armature on the base inwardly thereof I and comprising a core element, a winding on the core element, and a 106p of the winding'formed and disposed to be looped around a field 'pole of the generator, ,said base being of pan form and provided with a peripheral flange adapted to overlap the outer edge of the aperture.

: DALE S. COLE.

- ,LEONARD S. SPE'I'H. 

